Patient interface for ophthalmologic diagnostic and interventional procedures

ABSTRACT

Configurations are described for conducting ophthalmic procedures to address cataract-related clinical challenges. In one embodiment, a one-piece patient contact interface may be utilized to couple a diagnostic and/or interventional system to a cornea of a patient; in another embodiment, a two-part configuration may be utilized; in another embodiment, a liquid interface two-part embodiment may be utilized.

RELATED APPLICATION DATA

The present application claims priority to and is a continuation of U.S.patent application Ser. No. 13/225,373, filed Sep. 2, 2011, which claimsthe benefit under 35 U.S.C. § 119 to U.S. provisional patent applicationSer. No. 61/402,733, filed Sep. 2, 2010. The foregoing applications arehereby incorporated by reference into the present application in theirentirety.

FIELD OF THE INVENTION

The present invention relates to ophthalmic surgical procedures andsystems.

BACKGROUND

Cataract extraction is one of the most commonly performed surgicalprocedures in the world with approximately 4 million cases performedannually in the United States and 15 million cases worldwide. Thismarket is composed of various segments including intraocular lenses forimplantation, viscoelastic polymers to facilitate surgical maneuvers,disposable instrumentation including ultrasonic phacoemulsificationtips, tubing, and various knives and forceps. Modern cataract surgery istypically performed using a technique termed “phacoemulsification” inwhich an ultrasonic tip with an associated water stream for coolingpurposes is used to sculpt the relatively hard nucleus of the lens aftercreation of an opening in the anterior lens capsule termed “anteriorcapsulotomy” or more recently “capsulorhexis”. Following these steps aswell as removal of residual softer lens cortex by aspiration methodswithout fragmentation, a synthetic foldable intraocular lens, or “IOL”,may be inserted into the eye through a small incision.

One of the earliest and most critical steps in the procedure is thecreation, or performance, of capsulorhexis. This step evolved from anearlier technique termed “can-opener capsulotomy” in which a sharpneedle was used to perforate the anterior lens capsule in a circularfashion followed by the removal of a circular fragment of lens capsuletypically in the range of 5-8 mm in diameter. This facilitated the nextstep of nuclear sculpting by phacoemulsification. Due to a variety ofcomplications associated with variations of the can-opener technique,attempts were made by leading experts in the field to develop a bettertechnique for removal of the anterior lens capsule preceding theemulsification step. The concept of the capsulorhexis is to provide asmooth continuous circular opening through which not only thephacoemulsification of the nucleus can be performed safely and easily,but also for easy insertion of the intraocular lens. It provides both aclear central access for insertion, a permanent aperture fortransmission of the image to the retina by the patient, and also asupport of the IOL inside the remaining capsule that would limit thepotential for dislocation.

More modern techniques, such as those employing lasers to assist withthe creation of precision capsulorhexis geometries as well as otherdesired incisions, such as tissue structure relaxing incisions ofvarious types, are disclosed, for example, in U.S. patent applicationSer. Nos. 11/328,970, 12/510,148, 12/048,182, 12/048,185, 12/702,242,12/048,186, 61/289,837, 61/293,357, 61/297,624, and 61/302,437, each ofwhich is incorporated by reference herein in its entirety. Each of thesetechnologies generally requires a patient interface—a structure to jointhe patient's eye and the laser and associated imaging systems, and tooptimize the interaction between the diagnostic and imaging technologiesand the pertinent patient tissue structures. There is a need for furtheroptimization of the patient interface options to advance the standard ofcare of the cataract patient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of a diagnostic/interventionalophthalmic system.

FIGS. 2A-2C illustrate aspects of patient interface configurationsfeaturing a focusing lens engaged adjacent a cornea of a patient.

FIGS. 3A-3C illustrate aspects of one-piece patient interfaceembodiments.

FIGS. 4A-4E illustrate aspects of two-piece patient interfaceembodiments.

FIGS. 5A-5C illustrate aspects of liquid interface two-piece patientinterface embodiments.

FIGS. 6A-6D illustrate aspects of techniques for utilizingconfigurations such as those described in reference to FIGS. 1-5C.

SUMMARY

One embodiment is directed to a system for intercoupling anophthalmologic interventional system to an eye of a patient, comprising:a. a hollow reservoir housing defining an interior volume and havingproximal and distal ends, wherein the distal end comprises a eyeinterface surface configured to be removably and sealably coupled to theeye of the patient, and wherein the proximal end is configured to bemechanically interfaced with the interventional system in a manner thatallows for open access to the interior volume for transporting liquidsor gases in or out of the interior volume; b. an optical element fixedlycoupled to the hollow reservoir housing and occupying a portion of theinterior volume; and c. a liquid layer formed within the interior volumeof the reservoir housing and positioned, via one or more loads thatinclude gravitational loads, between the optical element and the eye.The hollow reservoir housing may comprise two parts that may beremovably coupled to each other. The two parts may be removably coupledto each other using a configuration selected from the group consistingof: a vacuum coupling interface, an interference fit interface, anelectromagnetic coupling interface, a manually-actuated mechanicalinterface, and an electromechanically-actuated mechanical interface. Theoptical element may comprise a lens having proximal and distal surfaces.The distal surface of the lens may be a convex surface. The eyeinterface surface may comprise a compliant circumferential seal member.The seal member may comprise two circumferential layers with a vacuumspace interposed between the two layers. The system may further comprisea vacuum loading device configured to apply a vacuum load into thevacuum space. At least one of the circumferential layers may have atapered cross section. At least one of the circumferential layers maycomprise a shape that is at least partially spherical. The liquid layermay comprise about 2 cubic centimeters in volume.

The liquid layer may comprise a material selected from: water, saline,oil, viscoelastic gel, and perfluorocarbon liquid. The vacuum loadingdevice may be configured to apply a vacuum load of between about 200 mmof mercury and about 600 mm of mercury. The hollow reservoir housing maycomprise a proximal part and a distal part, wherein the optical elementis fixedly coupled to the distal part. The hollow reservoir housing maycomprise a proximal part and a distal part, and the optical element maybe fixedly coupled to the proximal part. The liquid layer may be inimmediate contact with the optical element.

DETAILED DESCRIPTION

As described briefly above, one embodiment of a cataract diagnostic andinterventional system may be implemented by a system that projects orscans an optical beam into a patient's eye (68), such as system (2)shown in FIG. 1 which includes an ultrafast (“UF”) light source 4 (e.g.a femtosecond laser). Using this system, a beam may be scanned in apatient's eye in three dimensions: X, Y, Z. In this embodiment, the UFwavelength can vary between 1010 nm to 1100 nm and the pulse width canvary from 100 fs to 10000 fs. The pulse repetition frequency can alsovary from 10 kHz to 250 kHz. Safety limits with regard to unintendeddamage to non-targeted tissue bound the upper limit with regard torepetition rate and pulse energy; while threshold energy, time tocomplete the procedure and stability bound the lower limit for pulseenergy and repetition rate. The peak power of the focused spot in theeye (68) and specifically within the crystalline lens (69) and anteriorcapsule of the eye is sufficient to produce optical breakdown andinitiate a plasma-mediated ablation process. Near-infrared wavelengthsare preferred because linear optical absorption and scattering inbiological tissue is reduced across that spectral range. As an example,laser (4) may be a repetitively pulsed 1035 nm device that produces 500fs pulses at a repetition rate of 100 kHz and an individual pulse energyin the ten microjoule range.

The laser (4) is controlled by control electronics (300), via an inputand output device (302), to create optical beam (6). Control electronics(300) may be a computer, microcontroller, etc. In this example, theentire system is controlled by the controller (300), and data movedthrough input/output device IO (302). A graphical user interface GUI 304may be used to set system operating parameters, process user input (UI)(306) on the GUI (304), and display gathered information such as imagesof ocular structures.

The generated UF light beam (6) proceeds towards the patient eye (68)passing through half-wave plate, (8), and linear polarizer, (10). Thepolarization state of the beam can be adjusted so that the desiredamount of light passes through half-wave plate (8) and linear polarizer(10), which together act as a variable attenuator for the UF beam (6).Additionally, the orientation of linear polarizer (10) determines theincident polarization state incident upon beamcombiner (34), therebyoptimizing beamcombiner throughput.

The UF beam proceeds through a shutter (12), aperture (14), and apickoff device (16). The system controlled shutter (12) ensures on/offcontrol of the laser for procedural and safety reasons. The aperturesets an outer useful diameter for the laser beam and the pickoffmonitors the output of the useful beam. The pickoff device (16) includesof a partially reflecting mirror (20) and a detector (18). Pulse energy,average power, or a combination may be measured using detector (18). Theinformation can be used for feedback to the half-wave plate (8) forattenuation and to verify whether the shutter (12) is open or closed. Inaddition, the shutter (12) may have position sensors to provide aredundant state detection.

The beam passes through a beam conditioning stage (22), in which beamparameters such as beam diameter, divergence, circularity, andastigmatism can be modified. In this illustrative example, the beamconditioning stage (22) includes a 2 element beam expanding telescopecomprised of spherical optics (24) and (26) in order to achieve theintended beam size and collimation. Although not illustrated here, ananomorphic or other optical system can be used to achieve the desiredbeam parameters. The factors used to determine these beam parametersinclude the output beam parameters of the laser, the overallmagnification of the system, and the desired numerical aperture (NA) atthe treatment location. In addition, the optical system (22) can be usedto image aperture (14) to a desired location (e.g. the center locationbetween the 2-axis scanning device 50 described below). In this way, theamount of light that makes it through the aperture (14) is assured tomake it through the scanning system. Pickoff device (16) is then areliable measure of the usable light.

After exiting conditioning stage (22), beam (6) reflects off of foldmirrors (28, 30, & 32). These mirrors can be adjustable for alignmentpurposes. The beam (6) is then incident upon beam combiner (34).Beamcombiner (34) reflects the UF beam (6) (and transmits both the OCT114 and aim 202 beams described below). For efficient beamcombineroperation, the angle of incidence is preferably kept below 45 degreesand the polarization where possible of the beams is fixed. For the UFbeam (6), the orientation of linear polarizer (10) provides fixedpolarization.

Following the beam combiner (34), the beam (6) continues onto thez-adjust or Z scan device (40). In this illustrative example thez-adjust includes a Galilean telescope with two lens groups (42 and 44)(each lens group includes one or more lenses). Lens group (42) movesalong the z-axis about the collimation position of the telescope. Inthis way, the focus position of the spot in the patient's eye (68) movesalong the z-axis as indicated. In general there is a fixed linearrelationship between the motion of lens (42) and the motion of thefocus. In this case, the z-adjust telescope has an approximate2.times.beam expansion ratio and a 1:1 relationship of the movement oflens (42) to the movement of the focus. Alternatively, lens group (44)could be moved along the z-axis to actuate the z-adjust, and scan. Thez-adjust is the z-scan device for treatment in the eye (68). It can becontrolled automatically and dynamically by the system and selected tobe independent or to interplay with the X-Y scan device described next.Mirrors (36 and 38) can be used for aligning the optical axis with theaxis of z-adjust device (40). After passing through the z-adjust device(40), the beam (6) is directed to the x-y scan device by mirrors (46 &48). Mirrors (46 & 48) can be adjustable for alignment purposes. X-Yscanning is achieved by the scanning device (50) preferably using twomirrors (52 & 54) under the control of control electronics (300), whichrotate in orthogonal directions using motors, galvanometers, or anyother well known optic moving device. Mirrors (52 & 54) are located nearthe telecentric position of the objective lens (58) and focussing lens(66) combination described below. Tilting these mirrors (52/54) causesthem to deflect beam (6), causing lateral displacements in the plane ofUF focus located in the patient's eye (68). Objective lens (58) may be acomplex multi-element lens element, as shown, and represented by lenses(60, 62, and 64). The complexity of the lens (58) will be dictated bythe scan field size, the focused spot size, the available workingdistance on both the proximal and distal sides of objective 58, as wellas the amount of aberration control. An f-theta lens 58 of focal length60 mm generating a spot size of 10.mu.m, over a field of 10 mm, with aninput beam size of 15 mm diameter is an example. Alternatively, X-Yscanning by scanner (50) may be achieved by using one or more moveableoptical elements (e.g. lenses, gratings) which also may be controlled bycontrol electronics (300), via input and output device (302).

The aiming and treatment scan patterns can be automatically generated bythe scanner (50) under the control of controller (300). Such patternsmay be comprised of a single spot of light, multiple spots of light, acontinuous pattern of light, multiple continuous patterns of light,and/or any combination of these. In addition, the aiming pattern (usingaim beam 202 described below) need not be identical to the treatmentpattern (using light beam 6), but preferably at least defines itsboundaries in order to assure that the treatment light is delivered onlywithin the desired target area for patient safety. This may be done, forexample, by having the aiming pattern provide an outline of the intendedtreatment pattern. This way the spatial extent of the treatment patternmay be made known to the user, if not the exact locations of theindividual spots themselves, and the scanning thus optimized for speed,efficiency and accuracy. The aiming pattern may also be made to beperceived as blinking in order to further enhance its visibility to theuser. An optional focussing lens (66), which also may be loosely termeda “contact lens”, which can be any suitable ophthalmic lens, can be usedto help further focus the optical beam (6) into the patient's eye (68)while helping to stabilize eye position. The positioning and characterof optical beam 6 and/or the scan pattern the beam 6 forms on the eye(68) may be further controlled by use of an input device such as ajoystick, or any other appropriate user input device (e.g. GUI 304) toposition the patient and/or the optical system.

The UF laser (4) and controller (300) can be set to target the surfacesof the targeted structures in the eye (68) and ensure that the beam (6)will be focused where appropriate and not unintentionally damagenon-targeted tissue. Imaging modalities and techniques described herein,such as for example, Optical Coherence Tomography (OCT), Purkinjeimaging, Scheimpflug imaging, confocal or nonlinear optical microscopy,fluorescence imaging, or ultrasound may be used to determine thelocation and measure the thickness of the lens and lens capsule toprovide greater precision to the laser focusing methods, including 2Dand 3D patterning. Laser focusing may also be accomplished using one ormore methods including direct observation of an aiming beam, OpticalCoherence Tomography (“OCT”), Purkinje imaging, Scheimpflug imaging,confocal or nonlinear optical microscopy, fluorescence imaging,ultrasound, or other known ophthalmic or medical imaging modalitiesand/or combinations thereof. In the embodiment of FIG. 1, an OCT device(100) is described, although other modalities are within the scope ofthe present invention. An OCT scan of the eye will provide informationabout the axial location of the anterior and posterior lens capsule, theboundaries of the cataract nucleus, as well as the depth of the anteriorchamber. This information is then be loaded into the control electronics(300), and used to program and control the subsequent laser-assistedsurgical procedure. The information may also be used to determine a widevariety of parameters related to the procedure such as, for example, theupper and lower axial limits of the focal planes used for cutting thelens capsule and segmentation of the lens cortex and nucleus, and thethickness of the lens capsule among others.

The OCT device (100) in FIG. 1 includes a broadband or a swept lightsource (102) that is split by a fiber coupler (104) into a reference arm(106) and a sample arm (110). The reference arm (106) includes a module(108) containing a reference reflection along with suitable dispersionand path length compensation. The sample arm (110) of the OCT device(100) has an output connector (112) that serves as an interface to therest of the UF laser system. The return signals from both the referenceand sample arms (106, 110) are then directed by coupler (104) to adetection device (128), which employs either time domain, frequency orsingle point detection techniques. In FIG. 1, a frequency domaintechnique is used with an OCT wavelength of 920 nm and bandwidth of 100nm. Exiting connector (112), the OCT beam (114) is collimated using lens(116). The size of the collimated beam (114) is determined by the focallength of lens (116). The size of the beam (114) is dictated by thedesired NA at the focus in the eye and the magnification of the beamtrain leading to the eye (68). Generally, OCT beam (114) does notrequire as high an NA as the UF beam (6) in the focal plane andtherefore the OCT beam (114) is smaller in diameter than the UF beam (6)at the beamcombiner (34) location. Following collimating lens (116) isaperture (118) which further modifies the resultant NA of the OCT beam(114) at the eye. The diameter of aperture (118) is chosen to optimizeOCT light incident on the target tissue and the strength of the returnsignal. Polarization control element (120), which may be active ordynamic, is used to compensate for polarization state changes which maybe induced by individual differences in corneal birefringence, forexample. Mirrors (122 & 124) are then used to direct the OCT beam 114towards beamcombiners (126 & 34). Mirrors (122 & 124) may be adjustablefor alignment purposes and in particular for overlaying of OCT beam(114) to UF beam (6) subsequent to beamcombiner (34). Similarly,beamcombiner (126) is used to combine the OCT beam (114) with the aimbeam (202) described below. Once combined with the UF beam (6)subsequent to beamcombiner (34), OCT beam (114) follows the same path asUF beam (6) through the rest of the system. In this way, OCT beam (114)is indicative of the location of UF beam (6). OCT beam (114) passesthrough the z-scan 40 and x-y scan (50) devices then the objective lens(58), focussing lens (66) and on into the eye (68). Reflections andscatter off of structures within the eye provide return beams thatretrace back through the optical system, into connector (112), throughcoupler (104), and to OCT detector (128). These return back reflectionsprovide the OCT signals that are in turn interpreted by the system as tothe location in X, Y, Z of UF beam (6) focal location.

OCT device (100) works on the principle of measuring differences inoptical path length between its reference and sample arms. Therefore,passing the OCT through z-adjust 40 does not extend the z-range of OCTsystem (100) because the optical path length does not change as afunction of movement of 42. OCT system (100) has an inherent z-rangethat is related to the detection scheme, and in the case of frequencydomain detection it is specifically related to the spectrometer and theoptical bandwidth of the light source. In the case of OCT system (100)used in FIG. 1, the z-range is approximately 3-5 mm in an aqueousenvironment. Passing the OCT beam (114) in the sample arm through thez-scan of z-adjust (40) allows for optimization of the OCT signalstrength. This is accomplished by focusing the OCT beam (114) onto thetargeted structure while accommodating the extended optical path lengthby commensurately increasing the path within the reference arm (106) ofOCT system (100).

Because of the fundamental differences in the OCT measurement withrespect to the UF focus device due to influences such as immersionindex, refraction, and aberration, both chromatic and monochromatic,care must be taken in analyzing the OCT signal with respect to the UFbeam focal location. A calibration or registration procedure as afunction of X, Y Z should be conducted in order to match the OCT signalinformation to the UF focus location and also to the relate to absolutedimensional quantities.

Observation of an aim beam may also be used to assist the user todirecting the UF laser focus. Additionally, an aim beam visible to theunaided eye in lieu of the infrared OCT and UF beams can be helpful withalignment provided the aim beam accurately represents the infrared beamparameters. An aim subsystem (200) is employed in the configurationshown in FIG. 1. The aim beam (202) is generated by an aim beam lightsource (201), such as a helium-neon laser operating at a wavelength of633 nm. Alternatively a laser diode in the 630-650 nm range could beused. The advantage of using the helium neon 633 nm beam is its longcoherence length, which would enable the use of the aim path as a laserunequal path interferometer (LUPI) to measure the optical quality of thebeam train, for example. Once the aim beam light source generates aimbeam (202), the aim beam (202) is collimated using lens (204). The sizeof the collimated beam is determined by the focal length of lens (204).The size of the aim beam (202) is dictated by the desired NA at thefocus in the eye and the magnification of the beam train leading to theeye (68). Generally, aim beam (202) should have close to the same NA asUF beam (6) in the focal plane and therefore aim beam (202) is ofsimilar diameter to the UF beam at the beamcombiner (34) location.Because the aim beam is meant to stand-in for the UF beam (6) duringsystem alignment to the target tissue of the eye, much of the aim pathmimics the UF path as described previously. The aim beam (202) proceedsthrough a half-wave plate (206) and linear polarizer (208). Thepolarization state of the aim beam (202) can be adjusted so that thedesired amount of light passes through polarizer (208). Elements 206 &208 therefore act as a variable attenuator for the aim beam (202).Additionally, the orientation of polarizer (208) determines the incidentpolarization state incident upon beamcombiners (126 and 34), therebyfixing the polarization state and allowing for optimization of thebeamcombiners' throughput. Of course, if a semiconductor laser is usedas aim beam light source (200), the drive current can be varied toadjust the optical power. The aim beam (202) proceeds through a shutter(210) and aperture (212). The system controlled shutter (210) provideson/off control of the aim beam (202). The aperture (212) sets an outeruseful diameter for the aim beam (202) and can be adjustedappropriately. A calibration procedure measuring the output of the aimbeam (202) at the eye can be used to set the attenuation of aim beam(202) via control of polarizer (206). The aim beam (202) next passesthrough a beam conditioning device (214). Beam parameters such as beamdiameter, divergence, circularity, and astigmatism can be modified usingone or more well known beaming conditioning optical elements. In thecase of an aim beam (202) emerging from an optical fiber, the beamconditioning device (214) can simply include a beam expanding telescopewith two optical elements (216 and 218) in order to achieve the intendedbeam size and collimation. The final factors used to determine the aimbeam parameters such as degree of collimation are dictated by what isnecessary to match the UF beam (6) and aim beam (202) at the location ofthe eye (68). Chromatic differences can be taken into account byappropriate adjustments of beam conditioning device (214). In addition,the optical system (214) is used to image aperture (212) to a desiredlocation such as a conjugate location of aperture (14). The aim beam(202) next reflects off of fold mirrors (222 & 220), which arepreferably adjustable for alignment registration to UF beam (6)subsequent to beam combiner (34). The aim beam (202) is then incidentupon beam combiner (126) where the aim beam (202) is combined with OCTbeam (114). Beamcombiner (126) reflects the aim beam (202) and transmitsthe OCT beam (114), which allows for efficient operation of thebeamcombining functions at both wavelength ranges. Alternatively, thetransmit and reflect functions of beamcombiner (126) can be reversed andthe configuration inverted. Subsequent to beamcombiner (126), aim beam(202) along with OCT beam (114) is combined with UF beam (6) bybeamcombiner (34).

A device for imaging the target tissue on or within the eye (68) isshown schematically in FIG. 1 as imaging system (71). Imaging systemincludes a camera (74) and an illumination light source (86) forcreating an image of the target tissue. The imaging system (71) gathersimages which may be used by the system controller (300) for providingpattern centering about or within a predefined structure. Theillumination light source (86) for the viewing is generally broadbandand incoherent. For example, light source (86) can include multiple LEDsas shown. The wavelength of the viewing light source (86) is preferablyin the range of 700 nm to 750 nm, but can be anything which isaccommodated by the beamcombiner (56), which combines the viewing lightwith the beam path for UF beam (6) and aim beam (202) (beamcombiner 56reflects the viewing wavelengths while transmitting the OCT and UFwavelengths). The beamcombiner (56) may partially transmit the aimwavelength so that the aim beam (202) can be visible to the viewingcamera (74). Optional polarization element (84) in front of light source(86) can be a linear polarizer, a quarter wave plate, a half-wave plateor any combination, and is used to optimize signal. A false color imageas generated by the near infrared wavelength is acceptable. Theillumination light from light source (86) is directed down towards theeye using the same objective lens (58) and focussing lens (66) as the UFand aim beam (6, 202). The light reflected and scattered off of variousstructures in the eye (68) are collected by the same lenses (58 & 66)and directed back towards beamcombiner (56). There, the return light isdirected back into the viewing path via beam combiner and mirror (82),and on to camera (74). Camera (74) can be, for example but not limitedto, any silicon based detector array of the appropriately sized format.Video lens (76) forms an image onto the camera's detector array whileoptical elements (80 & 78) provide polarization control and wavelengthfiltering respectively. Aperture or iris (81) provides control ofimaging NA and therefore depth of focus and depth of field. A smallaperture provides the advantage of large depth of field which aids inthe patient docking procedure. Alternatively, the illumination andcamera paths can be switched. Furthermore, aim light source (200) can bemade to emit in the infrared which would not directly visible, but couldbe captured and displayed using imaging system (71). Coarse adjustregistration is usually needed so that when the focussing lens (66)comes into contact with the cornea, the targeted structures are in thecapture range of the X, Y scan of the system. Therefore a dockingprocedure is preferred, which preferably takes in account patient motionas the system approaches the contact condition (i.e. contact between thepatient's eye (68) and the focussing lens (66). The viewing system (71)is configured so that the depth of focus is large enough such that thepatient's eye (68) and other salient features may be seen before thefocussing lens (66) makes contact with eye (68). Preferably, a motioncontrol system (70) is integrated into the overall control system (2),and may move the patient, the system (2) or elements thereof, or both,to achieve accurate and reliable contact between the focussing, or“contact”, lens (66), the housing thereof, and/or the eye (68).Furthermore, as described below, vacuum suction subsystem and flange maybe incorporated into the system and used to stabilize the interfacingbetween the focusing lens (66), pertinent housing thereof, and the eye(68). In one embodiment the physical alignment of the eye (68) relativeto other portions of the system (2) via the focussing lens (66) may beaccomplished while monitoring the output of the imaging system (71), andperformed manually or automatically by analyzing the images produced byimaging system (71) electronically by means of control electronics (300)via 10 (302). Force and/or pressure sensor feedback may also be used todiscern contact, as well as to initiate the vacuum subsystem.

FIG. 2A depicts one embodiment of a focussing lens (66) configurationwherein the distal aspect (178) of the lens (66) is placed into directcontact with the cornea (94). The scanned beam (90) exiting the system(88) crosses the proximal surface (176) of the lens (66), passes throughthe lens (66), exits across the distal surface (178) of the lens (66),crosses the cornea (94), and eventually reaches the crystalline lens(69) to facilitate interventional steps such as capsulorhexis. Aclose-up view is illustrated in FIG. 2B, to demonstrate the notion ofundesirable corneal folds (96), which may be associated with excessapplanation loads placed upon the cornea with contact lens (66)configurations having a relatively large radii of curvature relative tothat of the cornea (in such cases, relatively large applanation loadsmay be applied to ensure surface contact between the lens 66 and therelatively convex shape of the cornea 94). We have found that cornealfolds (96) can degrade the optical path to the interior of the eye,reducing the reliability of laser interaction with the tissue of theeye. Further, it is also generally desirable to minimize intraocularpressure during diagnostic and interventional procedures, and largeapplanation loads tend to increase intraocular pressure. As a result, inthe embodiments depicted in FIGS. 3A-3C and 4A-4E, comprise focusinglenses (66) with distal surface radii of curvature that aresubstantially close to that of the typical human cornea, thussubstantially mitigating applanation and/or interfacing loads, asdescribed in further detail below.

Referring to FIG. 2C, one embodiment of a patient interface (182), whichmay be referred to as a “one-piece” interface, is shown interfaced witha movable portion (160) of a diagnostic and interventional system suchas that described in reference to FIG. 1, the patient interface (182)comprising a corneal interface (130), a conical lower housing portion(132) which houses a focusing lens (66), and a cylindrical upper housingportion (134) with a proximal aspect configured to mechanicallyinterface and couple with the movable portion (160) of the diagnosticand interventional system. FIG. 3A illustrates a similar configuration,with the patient interface (182) removably coupled to the movableportion (160) of a diagnostic and interventional system. FIG. 3B shows acloser up orthogonal view of a patient interface (182) such as thatdepicted in FIGS. 2C and 3A. The proximal aspect of the cylindricalupper housing portion (134) forms a geometric coupling interface (136)configured for removable coupling with the movable portion (160) of adiagnostic and interventional system. FIG. 3C illustrates a crosssectional view of the embodiment of FIG. 3B to show the position of thefocusing lens (66) within the conical lower housing portion (132) aswell as the direct interfacing of the distal surface (140) of the lens(66) with the cornea (94), and the cross sectional features of theflexible (in one embodiment comprising a flexible material such assilicone) cornea interface (130), including a cross-sectionally bi-lobedcontact surface (142) that creates a vacuum channel (142) between thetwo lobes which may be utilized to removably couple the cornea interface(130) to the surface of the cornea (94) with an applied vacuum conditionsuch as between about 300 and 600 mm of mercury. In one embodiment, thedistal surface (140) of the lens (66) has a radius of curvature equal toabout 8.3 mm, which is slightly larger than that of the average humancornea (94), to provide an engagement configuration wherein the distalsurface (140) may be slowly engaged with the cornea at approximately thecenter of the distal surface (140), and then with increased engagementand very slight applanating loads, bubbles and fluids squeezed outwardfrom the center of contact, ultimately resulting in a relatively cleaninterfacing for diagnostic and interventional purposes. The shape of thecornea in the depiction of FIG. 3C is the unloaded (un-applanated)shape, to illustrate that there is an intentional mismatch between thedistal surface (140) and the unloaded corneal (94) shape in the depictedembodiment (in an actual loaded scenario, the surfaces would directlymeet, as described above).

Referring to FIGS. 4A-4E, another embodiment (may be referred to as a“two-piece” embodiment) is depicted, wherein a configuration such asthat shown in FIGS. 2C-3C may be deconstructed or decoupled to providefor convenient hand-manipulated placement (i.e., through the use of alightweight handle 150) of the bottom portion (148) before subsequentcoupling with the top portion (152) and movable portion (160) of adiagnostic and interventional system. Together, the top and bottomportions (152, 148) may comprise a “hollow reservoir housing” whichdefines an interior volume and is configured to be interfaced to the eyeas described herein. The top and bottom portions may be removablycoupled to each other using a vacuum coupling interface, an interferencefit (i.e., press fit) interface, an electromagnetic coupling interface(i.e., wherein a current is applied to enforce a junction, and thecurrent may be turned off to release the junction), a manually-actuatedmechanical interface (i.e., wherein a latch or fitting may be manuallyactuated or moved to enforce a locking or unlocking of the interface),or an electromechanically-actuated mechanical interface (i.e., wherein alatch or fitting may be electromechanically actuated or moved, such asby a solenoid or other actuator, to enforce a locking or unlocking ofthe interface). Referring to FIG. 4A, a patient's face (146) and eye(68) are shown with a bottom portion (148) coupled to the cornea and/orsclera of eye (68) using vacuum loads applied using a vacuum port (154)to bring a flexible interface such as those shown in FIGS. 2C-3C intoreleasable engagement with the cornea and/or sclera. The lower portionshown is FIG. 4A has relatively low mass and low moment of inertia, andmay be manipulated easily by hand into a desired position, after whichvacuum may be applied through the port (154) to create the temporaryengagement. Subsequently, the top portion (152) may be coupled to thebottom portion (148) with a mechanical interfacing (156) that maycomprise a slight interference fit (i.e., such as a snap fit), to forman assembled two-part patient interface (184) which may be coupled to amovable portion (160) of a diagnostic and interventional system, asdescribed above. FIGS. 4C and 4D depict another interfacing embodimentwherein a spring clamp (158) may be utilized to removably couple thebottom portion (148) and top portion (152). FIG. 4D is a cross sectionalview of the embodiment of FIG. 4C. FIG. 4E depicts another interfacingembodiment wherein a rotatable collet type coupling member (162) may beutilized to removably couple the bottom portion (148) and top portion(152), by hand-manipulated rotation of the coupling member (162)relative to the bottom portion (148).

FIGS. 5A-5C depict another two-part patient interface (186) embodiment(this embodiment may be referred to as a liquid interface two-partembodiment), comprising an optical element such as a focusing lenselement (92) similar to those described above (element 66) with theexception that the distal surface (178) of the focusing lens element(92) does not come into direct contact with the surface of the cornea(94) and/or sclera—rather, there is a liquid layer (172) interposedbetween the distal surface (178) of the focusing lens element (92) andthe cornea (94) and/or sclera. The optical element (92) may haveproximal and distal surfaces, and the distal surface may be a convexsurface. In one embodiment, the distal surface of the optical element(92) is directly interfaced (i.e., submerged or directly exposed to)with the liquid layer, leaving the liquid layer as the unifyingconnection between the eye and the optical element (92). In oneembodiment the liquid layer may comprise about 2 cubic centimeters ofliquid. The liquid may comprise a material such as water, saline, oil(such as silicon oil), ophthalmic viscoelastic gel, or perfluorocarbonliquid. In the depicted two-part embodiment, the optical element (92) isfixedly coupled to the top, or proximal, portion (152) of the patientinterface; in another embodiment, the optical element (92) may befixedly coupled to the bottom, or distal, portion (148) of the patientinterface. As shown in FIG. 5A, a conical bottom portion (160) iscoupled to a flexible interface (130) similar to those described abovein reference to the one-part and two-part patient interfaceconfigurations. As with the aforementioned embodiments, the flexibleinterface (130) may comprise a compliant circumferential seal memberwhich may comprise two or more circumferential layers with a vacuumspace interposed therebetween to facilitate vacuum-enforced coupling ofthe seal member against the tissue of the eye (using, for example, avacuum load between about 200 mm mercury and about 600 mm mercury, whichmay be applied or generated using a vacuum device such as a regulatedmechanical vacuum pump). At least one of the circumferential layers mayhave a cross sectional shape that is tapered (i.e., with the smallerportion of the taper more immediately adjacent the eye tissue), and atleast one of the circumferential layers may comprise a shape that is atleast partially spherical (i.e., akin to a slice of a spherical shape).A manual manipulation handle is coupled to the bottom portion (160) toallow for easy coupling of the relatively low mass and inertia bottomportion (160) to the cornea and/or sclera (for example, with couplingretention provided by vacuum through the vacuum port 154) beforeinterfacial (168) engagement of the bottom portion to the top portion(166), which is configured to be removably coupled to a movable portion(160) of a diagnostic and interventional system such as that describedin reference to FIG. 1 (for example, using a mechanical couplinginterface, vacuum, or other removable coupling means). As shown in FIGS.5A-5C, the interfacial engagement (168) preferably is configured suchthat the liquid layer (172) is open to the external environment (i.e.,to the atmospheric pressure configuration of the patient examination oroperating room) such that additional fluid may be added by direct pouror syringe (i.e., through one of the depicted access features 165);similarly, liquid may be poured out of the un-encapsulated environmentby changing the orientation of the patient and/or patient interfacerelative to gravity and pouring the liquid out (i.e., through one of thedepicted access features 165). The access features (165) may compriseone or more vents, ports, windows, or the like which provide directaccess between the volume defined for the liquid layer (172) and thenearby atmosphere. Such a configuration, which may be deemed an “openconfiguration” (as opposed to a closed or encapsulated configurationwherein a volume of liquid may be at least temporarily encapsulatedwithin a tank or other structure) wherein the liquid layer (172) hasimmediate access to the outside environment, is advantageous for severalreasons: a) open allows immediate access to the fluid pooled in thepatient interface as a liquid layer—which allows for easier filling,refilling, and draining; b) open allows for fluid to escape whencoupling a two-part design; without such easy escape, unwantedinterfacial pressures may be built up and/or accumulated; c) open allowsfor gas to more easily escape, and gas typically manifests itself in theliquid layer environment as bubbles, which suboptimally change theoptical scenario (i.e., they distort the treatment beam fidelity, andmay cause opacities or other unwanted optical distortions). FIGS. 5B and5C show two slightly different cross sectional views of the embodimentof FIG. 5A. Referring to FIG. 5B, a liquid layer (172) is showninterposed between the distal surface (178) of the focusing lens (92)and the cornea (94) and/or sclera, which are not in physical contactwith each other. The liquid layer (172) acts as a light-transmissivemedium. In the depicted embodiment, the liquid layer freely floats inthe bottom portion 164 before interfacial (168) coupling of the bottomportion (164) and top portion (166) (i.e., the liquid layer 172 restsdue to gravity in the bottom of the bottom portion 164 after the bottomportion 164 has been coupled to the cornea 94 and/or sclera using thebi-lobed lip portion 144, which may be fed vacuum through the vacuumchannels 170 which are connected to the vacuum port 154 shown in FIG.5C). In one embodiment, the outer diameter of the bi-lobed flexibleseals (144) is about 21 mm, and the inner diameter is about 14.5 mm,leaving about 14 mm of clear aperture available for a broad range ofinterventional laser cutting, including but not limited to cornealincisions such as limbal relaxation cuts, etc. One additional benefit ofthe liquid interface is that the optical characteristics of the lenselement (92) may be optimized without as much regard to the anatomicalfit of the proximal and distal face radii of curvature as with thedirect-contact style lens elements (for example, element 66 above).Further, there is greater freedom of materials selection for thefocusing lens (92). In one embodiment, the focusing lens (92) comprisesan approximately 13 mm thick piece of material commercially availableunder the tradename “BK-7”® from Schott North America, Inc. of Elmsford,N.Y., the lens (92) having an approximately 245 mm convex proximalsurface radius of curvature, and an approximately 68 mm convex proximalsurface radius of curvature. Additionally, the displacement of the lens(92) away from the cornea (94) and/or sclera better facilitates anteriorcorneal and/or scleral surface cutting via laser without lens particlecontamination. OCT imaging, as available, for example, in the systemdescribed in reference to FIG. 1, may be utilized to confirm thedimensions of the fluid gap between the cornea (94) and/or sclera andthe focusing element (92). In one embodiment the liquid or fluid layer(172) comprises saline. In other embodiments, liquids may be specifiedwith customized dispersive, refractive, bubble resisting, and otherqualities.

In another embodiment, the two main temporarily or removably coupleableportions of the patient interface structure (148, 152) may be morepermanently coupled (i.e., either before the procedure, or duringmanufacturing of the parts wherein they by be fixedly coupled to eachother or formed together as one construct), in the form of a “one-piece”liquid-facilitated patient interface, with features identical to thosedescribed above in reference to FIGS. 4A-5C, but without the decouplableinterface between such portions (148, 152).

Referring to FIGS. 6A-6D, various implementation embodiments utilizingconfigurations such as those described above are illustrated. Referringto FIG. 6A, subsequent to preoperative diagnostics and patientpreparation steps (320), a patient may be positioned in a substantiallyhorizontal position for patient interface docking (322) (i.e., due tothe desire to not fight gravity when using a one or two part embodiment;further, in a liquid interface two part embodiment, it is obviouslydesirable to not have the liquid spill out of the bottom portion). Withthe patient interface coupled to a movable portion of the system (324)(i.e., by a mechanical interface coupling, vacuum coupling, etc), themovable portion may be utilized to move the patient interface into adesirable interfacing position relative to the patient's cornea and/orsclera (326), where the patient interface may be removably coupled tothe cornea and/or sclera (for example, using vacuum, or mechanical loador pressure to create a liquid-tight seal which may also serve tostabilize the eye) (328). With the docking completed, the procedure maybe conducted along with intraoperative imaging (330). After completingthe procedure, the patient interface may be decoupled (i.e., byreleasing the vacuum) from the cornea and/or sclera (332).

Referring to FIG. 6B, another embodiment is depicted wherein the firsttwo and last two steps are the same as in the embodiment of FIG. 5A, andthe intermediate steps comprise providing a two-piece patient interfaceconfiguration that is removably couplable to the eye, to itself (i.e.,the two pieces), and proximally to the system (334), removably couplingthe bottom portion to the cornea and/or sclera (336), moving the systeminto a position whereby the top portion, when coupled to the bottomportion, may be easily coupled to the system (338), and coupling the topportion to the system (340).

Referring to FIG. 6C, an embodiment is depicted that is similar to thatof FIG. 6B, with the addition of an intermediary step 342 (i.e., toaccommodate a liquid interface two-part patient interface configuration)of adding liquid (i.e., by pouring it in, injecting it in with asyringe, etc) to the bottom portion after the bottom portion is coupledto the cornea and/or sclera. FIG. 6D illustrates an embodiment similarto that of FIG. 6C, with the exception that the liquid layer may beadded (342) before the bottom portion is fully coupled to the corneaand/or sclera (336). Such a configuration may lead to some leakage offluid between the bottom portion and the cornea and/or sclera andsubsequently into the vacuum system.

Various exemplary embodiments of the invention are described herein.Reference is made to these examples in a non-limiting sense. They areprovided to illustrate more broadly applicable aspects of the invention.Various changes may be made to the invention described and equivalentsmay be substituted without departing from the true spirit and scope ofthe invention. In addition, many modifications may be made to adapt aparticular situation, material, composition of matter, process, processact(s) or step(s) to the objective(s), spirit or scope of the presentinvention. Further, as will be appreciated by those with skill in theart that each of the individual variations described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentinventions. All such modifications are intended to be within the scopeof claims associated with this disclosure.

Any of the devices described for carrying out the subject diagnostic orinterventional procedures may be provided in packaged combination foruse in executing such interventions. These supply “kits” may furtherinclude instructions for use and be packaged in sterile trays orcontainers as commonly employed for such purposes.

The invention includes methods that may be performed using the subjectdevices. The methods may comprise the act of providing such a suitabledevice. Such provision may be performed by the end user. In other words,the “providing” act merely requires the end user obtain, access,approach, position, set-up, activate, power-up or otherwise act toprovide the requisite device in the subject method. Methods recitedherein may be carried out in any order of the recited events which islogically possible, as well as in the recited order of events.

Exemplary aspects of the invention, together with details regardingmaterial selection and manufacture have been set forth above. As forother details of the present invention, these may be appreciated inconnection with the above-referenced patents and publications as well asgenerally known or appreciated by those with skill in the art. Forexample, one with skill in the art will appreciate that one or morelubricious coatings (e.g., hydrophilic polymers such aspolyvinylpyrrolidone-based compositions, fluoropolymers such astetrafluoroethylene, hydrophilic gel or silicones) may be used inconnection with various portions of the devices, such as relativelylarge interfacial surfaces of movably coupled parts, if desired, forexample, to facilitate low friction manipulation or advancement of suchobjects relative to other portions of the instrumentation or nearbytissue structures. The same may hold true with respect to method-basedaspects of the invention in terms of additional acts as commonly orlogically employed.

In addition, though the invention has been described in reference toseveral examples optionally incorporating various features, theinvention is not to be limited to that which is described or indicatedas contemplated with respect to each variation of the invention. Variouschanges may be made to the invention described and equivalents (whetherrecited herein or not included for the sake of some brevity) may besubstituted without departing from the true spirit and scope of theinvention. In addition, where a range of values is provided, it isunderstood that every intervening value, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the invention.

Also, it is contemplated that any optional feature of the inventivevariations described may be set forth and claimed independently, or incombination with any one or more of the features described herein.Reference to a singular item, includes the possibility that there areplural of the same items present. More specifically, as used herein andin claims associated hereto, the singular forms “a,” “an,” “said,” and“the” include plural referents unless the specifically stated otherwise.In other words, use of the articles allow for “at least one” of thesubject item in the description above as well as claims associated withthis disclosure. It is further noted that such claims may be drafted toexclude any optional element. As such, this statement is intended toserve as antecedent basis for use of such exclusive terminology as“solely,” “only” and the like in connection with the recitation of claimelements, or use of a “negative” limitation.

Without the use of such exclusive terminology, the term “comprising” inclaims associated with this disclosure shall allow for the inclusion ofany additional element—irrespective of whether a given number ofelements are enumerated in such claims, or the addition of a featurecould be regarded as transforming the nature of an element set forth insuch claims. Except as specifically defined herein, all technical andscientific terms used herein are to be given as broad a commonlyunderstood meaning as possible while maintaining claim validity.

The breadth of the present invention is not to be limited to theexamples provided and/or the subject specification, but rather only bythe scope of claim language associated with this disclosure.

The invention claimed is:
 1. A system for intercoupling anophthalmologic interventional system to an eye of a patient, comprising:a. a hollow reservoir housing defining an interior volume and havingproximal an distal ends, wherein the distal end comprises a eyeinterface surface configured to be removably and sealably coupled to theeye of the patient, and wherein the proximal end is configured to bemechanically interfaced with the interventional system in a manner thatallows for open access to the interior volume for transporting liquidsor gases in or out of the interior volume; b. an optical element fixedlycoupled to the hollow reservoir housing and occupying a portion of theinterior volume; and c. a liquid layer formed within the interior volumeof the reservoir housing and positioned via one or more loads thatinclude gravitational loads, between the optical element and the eye,wherein the hollow reservoir comprises two parts that may be removablycoupled to each other, wherein the two parts are removably coupled toeach other using a configuration selected from the group consisting of:a vacuum coupling interface, an interference fit interface, anelectromagnetic coupling interface, and a electromechanically-actuatedmechanical interface, wherein the eye interface surface comprises acompliant circumferential seal member, and the seal member comprises twocircumferential layers with a vacuum space interposed between the twolayers.
 2. The system of claim 1, wherein the optical element comprisesa lens having proximal and distal surfaces.
 3. The system of claim 2,wherein the distal surface of the lens is a convex surface.
 4. Thesystem of claim 1, further comprising a vacuum loading device configuredto apply a vacuum load into the vacuum space.
 5. The system of claim 1,wherein at least one of the circumferential layers has a tapered crosssection.
 6. The system of claim 1, wherein at least one of thecircumferential layers comprise a shape that is at least partiallyspherical.
 7. The system of claim 1, wherein the liquid layer comprisesabout 2 cubic centimeters in volume.
 8. The system of claim 1, whereinthe liquid layer comprises a material selected from: water, saline, oil,viscoelastic gel, and perfluorocarbon liquid.
 9. The system of claim 4,wherein the vacuum loading device is configured to apply a vacuum loadof between about 200 mm of mercury and about 600 mm of mercury.
 10. Thesystem of claim 4, wherein the hollow reservoir housing comprises aproximal part and a distal part, and wherein the optical element isfixedly coupled to the distal part.
 11. The system of claim 4, whereinthe hollow reservoir housing comprises a proximal part and a distalpart, and wherein the optical element is fixedly coupled to the proximalpart.
 12. The system of claim 1, wherein the liquid layer is inimmediate contact with the optical element.